Treatment of primary and metastatic carcinoma

ABSTRACT

Disclosed are methods of treating a chemotherapy-resistant cancer, of treating a cholangiocarcinoma, of treating a metastatic carcinoma, and of treating a transition cell urothelial carcinoma by administering a therapeutically effective amount of an endothelin B (ET B ) receptor agonist and a chemotherapeutic agent to a subject afflicted with such a cancer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit under 35 U.S.C. §119(e) toU.S. Provisional Application No. 61/644,704 filed May 9, 2012, theentire contents of which is hereby incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The present disclosure relates to medicine, cancer, and morespecifically, to the treatment of primary and metastatic carcinomas withcombination therapies.

BACKGROUND

Successful treatment of cancer, including primary and metastatic solidtumors, remains an unfulfilled medical goal, despite increasedunderstanding of the molecular biology of tumor cells and theavailability of an increased number of potential therapeutic agents.

One problem in the treatment of cancers is that an effective dose of awide variety of potential chemotherapeutic agents is restricted by thenon-selective, highly toxic effect of these agents on normal tissues. Asa result, many patients suffer from the side effects of chemotherapywithout reaping the benefits of the treatment. A related problem is anoften poor, and thus therapeutically-deficient, delivery of thechemotherapeutic drug specifically to the tumor. Thus, there is anecessity to develop more specific and less toxic cancer therapies.

Another problem is related to the identification of the cancer forproper treatment. Typically the cancerous tissue is examined under amicroscope to determine the cell type, enabling a physician to determineif that type of cell is normally found in the part of the body fromwhich the tissue sample was taken, or whether it is metastatic. The useof immunohistochemistry enables identification of many of thesemetastases. It is theorized that metastasis always coincides with aprimary cancer, and, as such, is a tumor that started from a cancer cellor cells in another part of the body. However, over 10% of patients willhave metastases without a primary tumor found. In these cases, theprimary tumor as “unknown” or “occult,” and the patient is said to havea cancer of unknown primary origin. It is estimated that 3% of allcancers are of unknown primary origin. This can be problematic becauseeffective treatment of a cancer begins with its identification.

Although the cells in a metastatic tumor resemble those in the primarytumor, difficulties in treatment can arise because the metastatic cancermay have different characteristics than the primary cancer. Some cancershave been found to have a “metastatic signature”, or differences in theexpression of a subset of genes between the primary cancer and itsmetastasis. Accordingly, because of these genetic differences, aphysician cannot assume that successful treatment of a primary cancerwill be the same as treatment of a metastatic cancer, and vice versa.Thus there remains a need for effective treatments for both metastaticand primary cancers.

Further problems concern the treatment of inoperable cancers. Some ofthese inoperable cancers remain incurable by chemotherapy. For example,cholangiocarcinoma, a cancer of the bile ducts which drain bile from theliver into the small intestine, is considered to be an incurable andrapidly lethal disease unless all of its tumors can be fully resected.For non-resectable cases, the 5-year survival rate is 0% where thedisease is inoperable because distal lymph nodes show metastases, andless than 5% in general. Overall median duration of survival is lessthan 6 months in inoperable, untreated, otherwise healthy patients withtumors involving the liver. A steady increase in the incidence ofintrahepatic cholangiocarcinoma has been documented over the pastseveral decades in North America, Europe, Asia, and Australia.Unfortunately, most patients have advanced and inoperable disease at thetime of diagnosis. In these patients, their disease can be managed,though never cured, with chemotherapy and/or radiation therapy.

Similarly, transitional cell carcinoma (TCC, also termed urothelial cellcarcinoma or UCC) is another problematic cancer to treat. TCC typicallyoccurs in the urinary system, including the kidney, bladder, ureter,urethra, and/or urachus, and arises from the transition epithelium, atissue lining the inner surface of these hollow organs. TCC is the mostcommon tumor of the renal pelvis. Over 70,000 cases of bladder cancerare diagnosed annually in the United States. Upper urinary tract TCC isestimated to occur in 5% of all urothelial cancers and in less than 10%of renal tumors. Evidence indicates that the frequency of upper urinarytract malignancies is increasing. Treatment for limited stage TCC issurgical resection of the tumor, but reoccurrence is common due to thepresence of occult micrometastases at diagnosis. While five-yearsurvival rates in patients with invasion beyond muscle can approach 40percent, survival for patients with lymph node involvement does notexceed 10 percent. Chemotherapy for TCC consisting of the “MVAC” regimen(methotrexate, vinblastine, adriamycin and cisplatin) has been used withlimited success.

Thus, there remains a need for more effective chemotherapeutic treatmentof metastatic carcinoma, and for cholangiocarcinoma and TCC, especiallyin cases of inoperable disease.

SUMMARY

Cholangiocarcinoma, transition cell urothelial carcinoma, and metastaticcarcinomas can be treated with endothelin B (ET_(B)) receptor agonistsin combination with a chemotherapeutic agent. The ET_(B) receptoragonist targets ET_(B) receptors in tumor vasculature to enhance tumorblood flow, which, in turn enhances the response of variouschemotherapeutic agents in tumor bearing animals.

Generally described are methods of treating a cholangiocarcinoma,comprising: (a) administering a therapeutically effective amount of anET_(B) receptor agonist and a therapeutically effective amount ofchemotherapeutic agent to a subject suffering from a cholangiocarcinoma;and (b) detecting a reduction in the size or in the growth of thecholangiocarcinoma. In some embodiments, the ET_(B) receptor agonist isIRL-1620, and in certain embodiments, the therapeutically effectiveamount of IRL-1620 is about 5 μg/m² to about 11 μg/m², about 6 μg/m² toabout 10 μg/m², about 7 μg/m² to about 9 μg/m², about 5 μg/m², about 6μg/m², about 7 μg/m², about 8 μg/m², about 9 μg/m², about 10 μg/m², orabout 11 μg/m². In some embodiments, the chemotherapeutic agent isdocetaxel, and in particular embodiments, the therapeutically effectiveamount of docetaxel is about 60 mg/m² to about 75 mg/m², about 60 mg/m²,about 65 mg/m², about 70 mg/m² or about 75 mg/m².

In some embodiments, the cholangiocarcinoma can be a metastaticcholangiocarcinoma. In certain embodiments, the ET_(B) receptor agonistand the chemotherapeutic agent are administered simultaneously or areadministered as a single composition. In other embodiments, the ET_(B)receptor agonist and the chemotherapeutic agent are administeredsequentially. For example, the ET_(B) receptor agonist is administeredprior to the chemotherapeutic agent. In some embodiments, thecholangiocarcinoma being treated is unresponsive to taxane chemotherapy.

In another aspect, the disclosure provides methods of treating ametastatic carcinoma, comprising: (a) administering a therapeuticallyeffective amount of an ET_(B) receptor agonist and a chemotherapeuticagent to a subject suffering from a metastatic carcinoma; and (b)detecting a reduction in the size or in the growth of the metastaticcarcinoma. In some embodiments the ET_(B) receptor agonist is IRL-1620,and in particular embodiments, the therapeutically effective amount ofIRL-1620 is about 5 μg/m² to about 11 μg/m², about 6 μg/m² to about 10μg/m², about 7 μg/m² to about 9 μg/m², about 5 μg/m², about 6 μg/m²,about 7 μg/m², about 8 μg/m², about 9 μg/m², about 10 μg/m², or about 11μg/m². In some embodiments, the chemotherapeutic agent is docetaxel, andin particular embodiments, the therapeutically effective amount ofdocetaxel is about 60 mg/m² to about 75 mg/m², about 60 mg/m², about 65mg/m², about 70 mg/m² or about 75 mg/m². In certain embodiments, themetastatic carcinoma is a prostate cancer, an ovarian cancer, a breastcancer or a cholangiocarcinoma. In some embodiments, the ET_(B) receptoragonist and the chemotherapeutic agent are administered substantiallysimultaneously or are administered as a single composition. In otherembodiments, the ETB receptor agonist and the chemotherapeutic agent areadministered sequentially, such as where the ETB receptor agonist isadministered prior to the chemotherapeutic agent. In some embodiments,the cancer being treated is resistant to taxane chemotherapy.

In yet another aspect, the disclosure provides methods of treating atransition cell urothelial carcinoma, comprising: (a) administering atherapeutically effective amount of an ET_(B) receptor agonist and achemotherapeutic agent to a subject suffering from a transition cellurothelial carcinoma; and (b) detecting a reduction in the size or inthe growth of the transition cell urothelial carcinoma. In someembodiments, the ET_(B) receptor agonist is IRL-1620. In certainembodiments the therapeutically effective amount of IRL-1620 is about 5μg/m² to about 11 μg/m², about 6 μg/m² to about 10 μg/m², about 7 μg/m²to about 9 μg/m², about 5 μg/m², about 6 μg/m², about 7 μg/m², about 8μg/m², about 9 μg/m², about 10 μg/m², or about 11 μg/m². In someembodiments, the chemotherapeutic agent is docetaxel, and in particularembodiments, the therapeutically effective amount of docetaxel is about60 mg/m² to about 75 mg/m², about 60 mg/m², about 65 mg/m², about 70mg/m² or about 75 mg/m². In certain embodiments, the metastaticcarcinoma is a prostate cancer, an ovarian cancer, a breast cancer or acholangiocarcinoma. In some embodiments, the ET_(B) receptor agonist andthe chemotherapeutic agent are administered substantially simultaneouslyor are administered as a single composition. In other embodiments, theET_(B) receptor agonist and the chemotherapeutic agent are administeredsequentially, such as where the ET_(B) receptor agonist is administeredprior to the chemotherapeutic agent. In some embodiments, the carcinomabeing treated is resistant to taxane chemotherapy.

The disclosure also provides methods of treating achemotherapy-resistant cancer, comprising: (a) administering atherapeutically effective amount of an ET_(B) receptor agonist and atherapeutically effective amount of chemotherapeutic agent to a subjectsuffering from a chemotherapy-resistant cancer; and (b) detecting areduction in the size or in the growth of the cancer. In someembodiments, the ET_(B) receptor agonist is IRL-1620. In certainembodiments the therapeutically effective amount of IRL-1620 is about 5μg/m² to about 11 μg/m², about 6 μg/m² to about 10 μg/m², about 7 μg/m²to about 9 μg/m², about 5 μg/m², about 6 μg/m², about 7 μg/m², about 8μg/m², about 9 μg/m², about 10 μg/m², or about 11 μg/m². In someembodiments, the chemotherapeutic agent is docetaxel, and in particularembodiments, the therapeutically effective amount of docetaxel is about60 mg/m² to about 75 mg/m², about 60 mg/m², about 65 mg/m², about 70mg/m² or about 75 mg/m².

In certain embodiments, the chemotherapy-resistant cancer is a prostatecancer, an ovarian cancer, a breast cancer, or a cholangiocarcinoma. Insome embodiments, the ET_(B) receptor agonist and the chemotherapeuticagent are administered substantially simultaneously or are administeredas a single composition. In other embodiments, the ETB receptor agonistand the chemotherapeutic agent are administered sequentially, such aswhere the ETB receptor agonist is administered prior to thechemotherapeutic agent.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects of the present disclosure, the variousfeatures thereof, as well as the disclosure itself may be more fullyunderstood from the following description, when read together with theaccompanying drawings in which:

FIG. 1 is a representation of a CT scan of a cholangiocarcinoma in apatient unresponsive to previous treatment with a taxane-based drug (a)prior to chemotherapy with docetaxel and IRL-1620 and (b) after about 12weeks of chemotherapy with docetaxel and IRL 1620;

FIG. 2 is a representation of a CT scan of a lung metastasis from aprimary cholangiocarcinoma from a patient unresponsive to previoustreatment with a taxane-based drug (a) prior to chemotherapy withdocetaxel and IRL-1620 showing solid tumors, and (b) after about 9 weeksof chemotherapy with docetaxel and IRL-1620 showing a cavitation of thetumors;

FIG. 3 is a representation of a CT scan of a TCC urothelium in a patientunresponsive to previous treatment with a taxane-based drug (a) prior tochemotherapy with docetaxel and IRL-1620 showing solid tumors, and (b)after about 6 weeks of chemotherapy with docetaxel and IRL-1620 showinga cavitation of the tumors;

FIG. 4 is a representation of a CT of a TCC urothelium in a patientunresponsive to previous treatment with a taxane-based drug (a) prior tochemotherapy with docetaxel and IRL-1620 showing solid tumors, and (b)after about 6 weeks of chemotherapy with docetaxel and IRL-1620 showinga cavitation of the tumors.

DESCRIPTION

Throughout this application, various patents, patent applications, andpublications are referenced. The disclosures of these patents, patentapplications, and publications in their entireties are herebyincorporated by reference into this application in order to more fullydescribe the state of the art as known to those skilled therein as ofthe date of the invention described and claimed herein. The instantdisclosure will govern in the instance that there is any inconsistencybetween the patents, patent applications, and publications and thisdisclosure.

DEFINITIONS

For convenience, certain terms employed in the specification, examples,and appended claims are collected here. Unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art to which thisinvention belongs. The initial definition provided for a group or termherein applies to that group or term throughout the presentspecification individually or as part of another group, unless otherwiseindicated.

The terms “a” and “an” and “the” and similar referents used in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein is merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein.

The term “or” is used herein to mean, and is used interchangeably with,the term “and/or,” unless context clearly indicates otherwise.

As used herein, the terms “treat”, “treatment” and “contributing to thetreatment of” shall mean preventing, retarding the progression or growthof, shrinking, or eliminating a cancer including a solid tumor. As such,these terms include both medical therapeutic and/or prophylacticadministration, as appropriate.

As used herein, the term “substantially simultaneously” shall mean thattwo pharmaceutical preparations (i.e. an ET_(B) receptor agonist and achemotherapeutic agent) are administered at the same time. According tothis definition, “same time” should be read to include exactlysimultaneously as well as within about ten minutes.

The term “about” is used herein to mean a value − or +20% of a givennumerical value. Thus, “about 60%” means a value of between 60−(20% of60) and 60+(20% of 60) (i.e., between 48 and 70).

The term “subject”, as used herein, means any subject for whomdiagnosis, prognosis, or therapy is desired. For example, a subject canbe a mammal, e.g., a human or non-human primate (such as an ape, monkey,orangutan, or chimpanzee), a dog, cat, guinea pig, rabbit, rat, mouse,horse, cattle, or cow.

A “therapeutically effective amount” as used herein means an amounteffective to prevent development or growth of, to eliminate, to retardthe progression of, or to reduce the size of, a solid tumor.Determination of a therapeutically effective amount is well within thecapability of those skilled in the art, especially in light of thedetailed disclosure provided herein.

In reference to an ET_(B) receptor agonist, a “therapeutically effectiveamount” refers to that amount which is effective to dilate the bloodvessels of a tumor. Toxicity and therapeutic efficacy of the ET_(B)receptor agonist and the chemotherapeutic agent can be determined bystandard pharmaceutical procedures in cell cultures or experimentalanimals, e.g., determining the LD₅₀ (the dose lethal to 50% of thepopulation) and the ED₅₀ (the dose therapeutically effective in 50% ofthe population). The dose ratio between toxic and therapeutic effects isthe therapeutic index, which is expressed as the ratio between LD₅₀ andED₅₀. A high therapeutic index is preferred. The data obtained can beused in formulating a range of dosage for use in humans. The dosage ofthe active ingredients lies within a range of circulating concentrationsthat include the ED₅₀ with little or no toxicity. The dosage can varywithin this range depending upon the dosage form employed, and the routeof administration utilized.

General

The present disclosure relates to treatment of metastatic carcinomas andcertain primary carcinomas by targeted delivery of a chemotherapeuticagent using an ET_(B) receptor agonist. ET_(B) receptor agonistsselectively increase blood supply to solid tumors thus increasingdelivery of chemotherapeutic agents to a carcinoma being treated.Targeted delivery of chemotherapeutic agents to tumors has the advantageof enhancing the benefit of chemotherapeutic agents while minimizingtheir systemic toxic effects. Such targeted delivery also serves tolower the required dose of chemotherapeutic agents thus potentiallyreducing unacceptable adverse effects of these agents.

The targeted delivery of chemotherapeutic agents according to thedisclosure utilizes the distinctive features of tumor vasculature.Tumors greater than a few millimeters in size require a constantnutrient supply, and accordingly, develop their own vascular bed andblood flow. Without constant nourishment from these developing bloodvessels, the tumors become hypoxic and subsequently die. Duringangiogenesis, tumor blood vessels develop substantially differently fromnormal vasculature, and have different properties. Single layeredepithelial cells are the first hastily formed tumor blood vessels. Thesenewly formed tumor blood vessels do not have a smooth muscle layer orinnervation. Tumors also incorporate mature blood vessels that possessall their autoregulatory functions.

Vascular tone, or the degree to which blood vessels are dilated orconstricted, is governed by a host of endogenous factors (including H⁺,K⁺, Ca²⁺, pO₂, pCO₂ and NO), as well as other regulatory substances suchas endothelins. Endothelins are a family of cyclic peptides which bindto two distinct surface receptors ET_(A) and ET_(B). These receptorsmediate biological responses from a variety of stimuli, includingvasoactive polypeptides, growth factors, and hormones. ET_(B) receptorshave been found in, without limitation, ovarian cancers, Kaposi's tumor,breast carcinoma, and melanomas. Their increased expression, along withendothelins, has been found in solid tumors. Stimulation of ET_(B)receptors can cause an increase in blood supply to tumors throughvasodilation of tumor blood vessels.

Herein, ET_(B) receptor agonists can be used to selectively increaseblood flow to tumors to enhance the targeted delivery ofchemotherapeutic agents. While not being held to any particular theory,it is thought that endothelin agonists stimulate ET_(B) receptors todilate tumor blood vessels, thereby increasing blood flow and theresultant delivery of chemotherapeutic agents to the tumor. Theincreased blood perfusion of tumors caused by endothelin agonists alsoincreases oxygenation of the tissue. Improved oxygenation can enhancethe therapeutic action of chemotherapeutic agents. Endothelin also canhave mitogenic properties. The mitogenic actions of endothelin can helpincrease the action of chemotherapeutic agents, when administeredtogether. The mitogenic action of an endothelin agonist can increase theaction of chemotherapeutic agents by improving their incorporation intodividing cells, thus increasing their efficacy.

Cancers that are treated with the methods of the disclosure includesolid primary and metastatic cholangiocarcinomas and transition cellurothelial carcinomas. The present methods are also effective intreating metastatic carcinomas such as, without limitation, ovarian,gastrointestinal (including colon), breast, prostate, and liver tumors.Additionally, the present methods treat primary and metastaticchemotherapy-resistant cancers such as taxane-resistant prostate,breast, and ovarian cancers. Other cancers at least partially resistantto at least one of YM 155 (surviving inhibitor), AMG-820, gemcitabine,cisplatin, fluorouracil, fp-103, lupron, EDC-3263, FP-1039, taxol,carboplatin, and/or CP873,890 can also be treated by the methods of thedisclosure.

Useful ET_(B) receptor agonists according to the present method include,but are not limited to, one or more of IRL-1620, ET-1, ET-2, ET-3,BQ3020, sarafotoxin S6c, [Ala^(1, 3, 11, 15)]ET-1, and combinationsthereof.

One useful ET_(B) receptor agonist is IRL-1620 or N-Succunyl-[Glu⁹,Ala^(11,15)] Endothelin-1 (8-21). A 14 amino acid peptide succinylatedat its amino end, IRL-1620 has an amino acid sequence ofSuc-Asp-Glu-Glu-Ala-Val-Tyr-Phe-Ala-His-Leu-Asp-Ile-Ile-Trp-OH (SEQ IDNO: 1). It is an analog of ET-1 and binds specifically to ET_(B)receptors 120,000 times more selectively than it binds to endothelin Areceptors.

Useful chemotherapeutic agents include, without limitation, one or moreof docetaxel, alkylating agents, antimetabolites, hormones andantagonists thereof, radioisotopes, antibodies, as well as naturalproducts, and combinations thereof. For example, an ET_(B) receptoragonist can be administered with antibiotics, such as doxorubicin andother anthracycline analogs, nitrogen mustards, such as, withoutlimitation, cyclophosphamide, pyrimidine analogs such as, withoutlimitation, 5-fluorouracil, cisplatin, hydroxyurea, and its natural andsynthetic derivatives, and the like. As another example, in the case ofmixed tumors, such as adenocarcinoma of the breast, where the tumorsinclude gonadotropin-dependent and gonadotropin-independent cells, theET_(B) receptor agonist can be administered in conjunction with, withoutlimitation, leuprolide or goserelin (synthetic peptide analogs ofLH-RH). Additional non-limiting examples of chemotherapeutic agents thatcan be used with the present invention include adriamycin, camptothecin,carboplatin, cisplatin, daunorubicin, doxorubicin, interferon (alpha,beta, and/or gamma), interleukin 2, irinotecan, paclitaxel, topotecan,and therapeutically effective analogs, combinations, and derivatives ofthe same.

Pharmaceutical Compositions and Administration

The dose of ET_(B) receptor agonist and of the chemotherapeutic agentdepends on the agonist and agent being used and the patient beingtreated. The exact formulation and dosage can be determined by anindividual physician in view of the patient's condition. Dosage amountand interval can be adjusted individually to provide levels of theactive ingredients that are sufficient to maintain therapeutic orprophylactic effects. For example, the amount of pharmaceuticalcomposition administered can be dependent on the subject being treated,on the subject's weight, the severity of the affliction, the manner ofadministration, and the judgment of the prescribing physician.

The ET_(B) receptor agonist and the chemotherapeutic agent can beadministered alone, or in admixture with a pharmaceutically acceptablecarrier or excipient selected with regard to the intended route ofadministration and standard pharmaceutical practice. Pharmaceuticalcompositions for use in accordance with the present invention thus canbe formulated in a conventional manner using one or more physiologicallyacceptable carriers comprising excipients and auxiliaries thatfacilitate processing of the active ingredients into preparations whichcan be used pharmaceutically.

As used herein, a “pharmaceutically acceptable carrier” means a carrierthat can be administered to a subject together with an ET_(B) receptoragonist and/or chemotherapeutic agent described herein, which does notdestroy the pharmacological activity thereof. Pharmaceuticallyacceptable carriers include, e.g., solvents, dispersion media, coatings,antibacterial and antifungal agents, isotonic and absorption delayingagents, and the like, compatible with pharmaceutical administration.Supplementary active compounds can also be incorporated into thecompositions.

Non-limiting examples of pharmaceutically acceptable carriers that canbe used include poly(ethylene-co-vinyl acetate), PVA, partiallyhydrolyzed poly(ethylene-co-vinyl acetate), poly(ethylene-co-vinylacetate-co-vinyl alcohol), a cross-linked poly(ethylene-co-vinylacetate), a cross-linked partially hydrolyzed poly(ethylene-co-vinylacetate), a cross-linked poly(ethylene-co-vinyl acetate-co-vinylalcohol), poly-D, L-lactic acid, poly-L-lactic acid, polyglycolic acid,PGA, copolymers of lactic acid and glycolic acid (PLGA),polycaprolactone, polyvalerolactone, poly (anhydrides), copolymers ofpolycaprolactone with polyethylene glycol, copolymers of polylactic acidwith polyethylene glycol, polyethylene glycol; and combinations andblends thereof.

Other carriers include, e.g., aqueous gelatin, aqueous protein, apolymeric carrier, a cross-linking agent, or a combination thereof. Inanother instances, the carrier can be a matrix. In yet other instances,the carrier includes water, a pharmaceutically acceptable buffer salt, apharmaceutically acceptable buffer solution, a pharmaceuticallyacceptable antioxidant, ascorbic acid, one or more low molecular weightpharmaceutically acceptable polypeptides, a peptide comprising about 2to about 10 amino acid residues, one or more pharmaceutically acceptableproteins, one or more pharmaceutically acceptable amino acids, anessential-to-humans amino acid, one or more pharmaceutically acceptablecarbohydrates, one or more pharmaceutically acceptablecarbohydrate-derived materials, a non-reducing sugar, glucose, sucrose,sorbitol, trehalose, mannitol, maltodextrin, dextrins, cyclodextrin, apharmaceutically acceptable chelating agent, EDTA, DTPA, a chelatingagent for a divalent metal ion, a chelating agent for a trivalent metalion, glutathione, pharmaceutically acceptable nonspecific serum albumin,and/or combinations thereof.

A pharmaceutical composition containing an ET_(B) receptor agonistand/or a chemotherapeutic agent can be formulated to be compatible withits intended route of administration as known by those of ordinary skillin the art. Non-limiting examples of routes of administration includeparenteral, intravenous, intradermal, subcutaneous, oral (e.g.,inhalation), transdermal (topical), transmucosal, vaginal and rectaladministration. Solutions or suspensions used for parenteral,intradermal, or subcutaneous application can include the followingcomponents: a sterile diluent such as water for injection, salinesolution, fixed oils, polyethylene glycols, glycerine, propylene glycolor other synthetic solvents; antibacterial agents such as benzyl alcoholor methyl parabens; antioxidants such as ascorbic acid or sodiumbisulfite; chelating agents such as ethylenediaminetetraacetic acid;buffers such as acetates, citrates or phosphates and agents for theadjustment of tonicity such as sodium chloride or dextrose. The pH canbe adjusted with acids or bases, such as hydrochloric acid or sodiumhydroxide. The parenteral preparation can be enclosed in ampoules,disposable syringes or multiple dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injectable use include sterileaqueous solutions (where water soluble) or dispersions and sterilepowders for the extemporaneous preparation of sterile injectablesolutions or dispersion. For intravenous administration, suitablecarriers include physiological saline, bacteriostatic water,polyethoxylated castor oil, CREMOPHOR® EL (BASF, Parsippany, N.J.) orphosphate buffered saline (PBS). In all cases, the composition should besterile and should be fluid to the extent that easy syringabilityexists. The composition should be stable under the conditions ofmanufacture and storage and must be preserved against the contaminatingaction of microorganisms such as bacteria and fungi. The carrier can bea solvent or dispersion medium containing, for example, water, ethanol,polyol (for example, glycerol, propylene glycol, and liquidpolyetheylene glycol, and the like), and suitable mixtures thereof. Theproper fluidity can be maintained, for example, by the use of a coatingsuch as lecithin, by the maintenance of the required particle size inthe case of dispersion and by the use of surfactants. Prevention of theaction of microorganisms can be achieved by various antibacterial andantifungal agents, for example, parabens, chlorobutanol, phenol,ascorbic acid, thimerosal, and the like. It may be desirable to includeisotonic agents, for example, sugars, polyalcohols such as mannitol,sorbitol, or sodium chloride in the composition. Prolonged absorption ofthe injectable compositions can be accomplished by including in thecomposition an agent that delays absorption, for example, aluminummonostearate and gelatin (see, e.g., Remington: The Science and Practiceof Pharmacy, 21st edition, Lippincott Williams & Wilkins, Gennaro, ed.(2006)).

Sterile injectable solutions can be prepared by incorporating an ET_(B)receptor agonist and/or a chemotherapeutic agent in the required amountin an appropriate solvent with one or a combination of ingredientsenumerated above, as required, followed by filtered sterilization.Generally, dispersions are prepared by incorporating the active compoundinto a sterile vehicle that contains a basic dispersion medium and therequired other ingredients from those enumerated above. In the case ofsterile powders for the preparation of sterile injectable solutions, themethods of preparation include, without limitation, vacuum drying andfreeze-drying which yields a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

Oral compositions generally include an inert diluent or an ediblecarrier. For the purpose of oral therapeutic administration, an ET_(B)receptor agonist and/or chemotherapeutic agent can be incorporated withexcipients and used in the form of tablets, pills, troches, or capsules,e.g., gelatin capsules. Oral compositions can also be prepared using afluid carrier for use as a mouthwash. Pharmaceutically compatiblebinding agents, and/or adjuvant materials can be included as part of thecomposition. The tablets, pills, capsules, troches and the like cancontain any of the following ingredients, or compounds of a similarnature: a binder such as microcrystalline cellulose, gum tragacanth orgelatin; an excipient such as starch or lactose, a disintegrating agentsuch as alginic acid, Primogel, or corn starch; a lubricant such asmagnesium stearate or Sterotes; a glidant such as colloidal silicondioxide; a sweetening agent such as sucrose or saccharin; or a flavoringagent such as peppermint, methyl salicylate, or orange flavoring.

For administration by inhalation, an ET_(B) receptor agonist and/or achemotherapeutic agent can be delivered in the form of an aerosol sprayfrom pressured container or dispenser that contains a suitablepropellant, e.g., a gas such as carbon dioxide, or a nebulizer.

Systemic administration can also be by transmucosal or transdermalmeans. For transmucosal or transdermal administration, penetrantsappropriate to the barrier to be permeated are used in the formulation.Such penetrants are generally known in the art, and include, but are notlimited to, for example, for transmucosal administration, detergents,bile salts, and fusidic acid derivatives. Transmucosal administrationcan be accomplished through the use of nasal sprays or suppositories.For transdermal administration, the active compounds are formulatedinto, e.g., ointments, salves, gels, or creams as generally known in theart.

The pharmaceutical compositions containing an ET_(B) receptor agonistand/or a chemotherapeutic agent can also be prepared in the form ofsuppositories (e.g., with conventional suppository bases such as cocoabutter and other glycerides) or retention enemas for rectal delivery.

Some pharmaceutical compositions can be prepared with a carrier thatprotects the ET_(B) receptor agonist and/or the chemotherapeutic agentagainst rapid elimination from the body, such as a controlled releaseformulation, including implants and microencapsulated delivery systems(as described, e.g., in Tan et al., Pharm. Res. 24:2297-2308, 2007).Biodegradable, biocompatible polymers can be used, such as ethylenevinyl acetate, polyanhydrides, polyglycolic acid, collagen,polyorthoesters, and polylactic acid. Methods for preparation of suchformulations are apparent to those skilled in the art. The materials canalso be obtained commercially (e.g., from Alza Corp., Mountain View,Calif.). Liposomal suspensions (including liposomes with the ET_(B)receptor agonist and/or the chemotherapeutic agent on their surface) canalso be used as pharmaceutically acceptable carriers. These can beprepared according to methods known to those skilled in the art, e.g.,as described in U.S. Pat. No. 4,522,811.

It may be advantageous to formulate oral or parenteral compositions indosage unit form for ease of administration and uniformity of dosage.Dosage unit form as used herein refers to physically discrete unitssuited as unitary dosages for the subject to be treated; each unitcontaining a predetermined quantity of active compound calculated toproduce the desired therapeutic effect in association with the requiredpharmaceutical carrier.

Toxicity and therapeutic efficacy of the ET_(B) receptor agonist and/orthe chemotherapeutic agent such compounds can be determined by standardpharmaceutical procedures in cell cultures or experimental animals,e.g., for determining the LD₅₀ (the dose lethal to 50% of thepopulation) and the ED₅₀ (the dose therapeutically effective in 50% ofthe population). The dose ratio between toxic and therapeutic effects isthe therapeutic index and it can be expressed as the ratio LD₅₀/ED₅₀.While compounds that exhibit toxic side effects can be used, care shouldbe taken to design a delivery system that targets such compounds to thesite of affected tissue in order to minimize potential damage touninfected cells and, thereby, reduce side effects. For example, a dosecan be formulated in animal models to achieve a circulating plasmaconcentration range that includes the IC₅₀ (i.e., the concentration ofthe test compound which achieves a half-maximal inhibition of symptoms)as determined in cell culture. Such information can be used to moreaccurately determine useful doses in humans. Levels in plasma can bemeasured, for example, by high performance liquid chromatography.Information for preparing and testing such compositions are known in theart (see, e.g., Remington's The Science and Practice of Pharmacy, 21stedition, Lippincott Williams & Wilkins, Gennaro, ed. (2006)).

The data obtained from cell culture assays and animal studies can beused in formulating a range of dosage for use in humans. The dosage ofsuch compounds lies generally within a range of circulatingconcentrations that include the ED₅₀ with little or no toxicity. Thedosage can vary within this range depending upon the dosage formemployed and the route of administration utilized. For any compounddescribed herein, the therapeutically effective dose can be estimatedinitially from cell culture assays. A dose can be formulated in animalmodels to achieve a circulating plasma concentration range that includesthe IC₅₀ (i.e., the concentration of the test compound which achieves ahalf-maximal inhibition of symptoms) as determined in cell culture. Suchinformation can be used to more accurately determine useful doses inhumans. Levels in plasma can be measured, for example, by highperformance liquid chromatography. Information for preparing and testingsuch compositions are known in the art (see, e.g., Remington's TheScience and Practice of Pharmacy, 21st edition, Lippincott Williams &Wilkins, Gennaro, ed. (2006)).

A therapeutically effective amount of a chemotherapeutic agent depends,in part, on the patient, the cancer to be treated and the route ofadministration. In some instances, a therapeutically effective amount ordosage of a chemotherapeutic agent can range from about 0.001 mg/kg bodyweight to about 100 mg/kg body weight, e.g., from about 0.01 mg/kg bodyweight to about 50 mg/kg body weight, from about 0.025 mg/kg body weightto about 25 mg/kg body weight, from about 0.1 mg/kg body weight to about20 mg/kg body weight, from about 0.25 mg/kg body weight to about 20mg/kg body weight, from about 0.5 mg/kg body weight to about 20 mg/kgbody weight, from about 0.5 mg/kg body weight to about 10 mg/kg bodyweight, from about 1 mg/kg body weight to about 10 mg/kg body weight, orabout 5 mg/kg body weight. Dosages can also be in mg/m² a dosing unitused for many chemotherapy drugs based on body surface area (BSA), i.e.,mg per body surface area of patient. In a specific example, atherapeutically effective dose of docetaxel is from about 60 mg/m² toabout 75 mg/m².

Likewise, a therapeutically effective amount of ET_(B) receptor agonistdepends, in part, on the patient, the cancer to be treated and the routeof administration. The dose of ET_(B) receptor agonist administered isan amount effective to dilate the blood vessels of the tumor to betreated. For example, in some non-limiting instances, therapeuticallyeffective amounts of intravenously administered IRL-1620 are about 0.5μg/m², about 1 μg/m² to about 12 μg/m², from about 5 μg/m² to about 11μg/m², or about 11 μg/m². In one example, the maximum tolerated dosageof IRL-1620 in combination with docetaxel is 11 μg/m². In one example,the maximum tolerated dosage of IRL-1620 in combination with docetaxelis 15.1 μg/m².

A physician will appreciate that certain factors may influence thedosage required to effectively treat a subject, including but notlimited to the severity of the cancer, previous treatments, the generalhealth and/or age of the subject, and other diseases present. It willalso be appreciated that the effective dosage of an ET_(B) receptoragonist and/or a chemotherapeutic agent used for treatment may increaseor decrease over the course of a particular treatment.

Treatment of a subject with a therapeutically effective amount of ET_(B)receptor agonist depends, in part, on the patient, the cancer to betreated and the route of administration and/or a chemotherapeuticagent-containing pharmaceutical composition described herein can be asingle treatment, continuous treatment, or a series of treatmentsdivided into multiple doses. The treatment can include a singleadministration, continuous administration, or periodic administrationover one or more years. Chronic, long-term administration can beindicated in many cases. In some instances, a subject is treated for upto two years, for up to 1.5 years, or for up to one year. In otherinstances, a subject is treated for up to 74 weeks. In other instances,a subject is treated for up to 6 months. In particular instances, asubject is treated from about 40 to about 75 weeks. In some embodiments,the subject is treated for a bout 20 to about 40 weeks, or from 20 toabout 74 weeks, or for 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75,80, 85, 90, 95, or 100 weeks. In yet another situation, a subject istreated for up to 100 days. In some examples, a subject is treated withIRL-1620 and docetaxel in a time frame of one time per week for up to 10weeks, or alternatively between 2 weeks to 8 weeks, between about 3weeks to 7 weeks, or for about 4 weeks, 5 weeks, 6 weeks, 10 week to 80weeks, 20 weeks to 40 weeks, or 40 weeks to 74 weeks In other instances,a subject can be treated substantially continuously for the same amountsof time listed above. In other situations, a subject can be treated onceper day, twice per day, once per week, or once per month.

The ET_(B) receptor agonist and the chemotherapeutic agent can beadministered substantially simultaneously or can be administeredsequentially (with the chemotherapeutic agent administered prior to theET_(B) receptor agonist or the ET_(B) receptor agonist administeredprior to the chemotherapeutic agent). In certain non-limiting exampleswhere the ET_(B) receptor agonist and the chemotherapeutic agent areadministered substantially simultaneously, they can be administered as asingle composition.

Aspects of the present specification disclose, in part, a kit comprisingcomponents useful in performing any of the methods disclosed herein. Inone embodiment, a kit comprises an ET_(B) receptor agonist and achemotherapeutic agent.

Instructions as disclosed herein may be present in the subject kits in avariety of forms, one or more of which may be present in the kit. Oneform in which these instructions may be present is as printedinformation on a suitable medium or substrate, e.g., a piece or piecesof paper on which the information is printed, in the packaging of thekit, in a package insert, etc. Yet another means would be a computerreadable medium, e.g., diskette, tape, or CD., on which the informationhas been recorded. Yet another means that may be present is a websiteaddress which may be used via the internet to access the information ata removed site. Any convenient means may be present in the kits.

For veterinary use, the active ingredients are administered as asuitably acceptable formulation in accordance with normal veterinarypractice. The veterinarian can readily determine the dosing regimen thatis most appropriate for a particular animal.

EXAMPLES

Reference will now be made to specific examples illustrating thedisclosure. It is to be understood that the examples are provided toillustrate preferred embodiments and that no limitation to the scope ofthe disclosure is intended thereby.

Example 1 IRL-1620 and Docetaxel Treatment of Carcinoma

This study was a 2-part, open label, single arm, dose escalation studyof the ET_(B) receptor agonist, IRL-1620 in combination with thechemotherapeutic agent, docetaxel.

Part 1 of the study defined maximum toxic dosage (MTD), optimal dose ofIRL-1620, and measured PK/PD profiles.

Patients with progressive or recurrent carcinoma who failed all standardtherapies were eligible for the study. Patients with a history of CHF,stroke, symptomatic COPD, ventricular arrhythmia were excluded from thestudy. 30 patients were enrolled in part 1 of the study. Patientcharacteristics were as follows. 14 men and 16 women with a median ageof 61 years (range 41-77) took part in the study. 9 patients hadprostate cancer, 3 had breast cancer, 4 had female reproductivemalignancies (ovarian, cervical, or endometrial cancers), 3 hadGI-related malignancies (cholangiocarcinoma, esophageal or gastriccancers), 2 had pancreatic cancers, and 9 had omental, lung,adenocortical, anal, neuroendocrine, soft tissue sarcoma, or renalcancers.

Eligible patients received IRL-1620 delivered intravenously over oneminute on Days 1, 8 and 15. On Day 8 patients underwent a series of fourH₂ ¹⁵O PET Blood Flow (BF) scans to assess alterations in BF induced byIRL-1620 in tumor and non-tumor regions. Fifteen minutes after receivingIRL-1620 on Day 15, patients received docetaxel, 60 mg/m², administeredby infusion over 1 hour.

Part 2 of the study focuses on the safety and tolerability of docetaxeladministered at a dose of 75 mg/m² following IRL-1620 at MTD and anadditional dose in 2 groups. CT or MRI scans are used to assess thepatient's tumor size. A series of dynamic contrast enhancer pattern MRIscans are used to measure any increases in blood flow induced by IRL1620.

IRL-1620 dose levels administered were 0.5 μg/m² (n=1), 1.0 μg/m² (n=1),2.0 μg/m² (n=3), 2.8 μg/m² (n=3), 3.7 μg/m² (n=1), 3.9 μg/m² (n=4), 5.5μg/m² (n=3), 7.7 μg/m² (n=3), 10.8 μg/m² (n=4), 15.1 μg/m² (n=3), 10.8μg/m² (n=4). The docetaxel dose level was 60 mg/m² or 75 mg/m².

Dose limiting toxicities were observed at a dose of 15.1 μg/m² ofIRL-1620. Maximum tolerated dose was defined as 11 μg/m². Drug relatedserious adverse events were (n; %): ischemic stroke (1, 0.03), dyspnea(1, 0.03), pleural effusion (1, 0.03). Disease progression was the mostcommon reason for the discontinuation of the study (84%).

There were 5 cases of stable disease (16% SD). Prolonged clinicalbenefit was observed in 4 cases (13%) where patients stayed on the studyfor 20-74 weeks. A PSA response in previously docetaxel treated prostatecancer patient as well as a measurable decrease in metastatic prostatecancer. Anti-tumor activity was seen in patients withdocetaxel-pretreated patients. One patient with cholangiocarcinomaachieved complete regression of lung metastasis within 3 months oftreatment and stayed on the study for 41 weeks before eventuallyprogressing. Treatment with IRL-1620 did not result in any measurablechanges in blood flow.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain, usingno more than routine experimentation, numerous equivalents to thespecific composition and procedures described herein. Such equivalentsare considered to be within the scope of this invention, and are coveredby the following claims.

1. A method of treating a chemotherapy-resistant cancer, comprising:administering a therapeutically effective amount of an endothelin B(ET_(B)) receptor agonist and a therapeutically effective amount ofchemotherapeutic agent to a subject suffering from achemotherapy-resistant cancer; wherein administration results in areduction in the size or in the growth of the chemotherapy-resistantcancer, thereby treating the chemotherapy-resistant cancer.
 2. Themethod of claim 1, wherein the ET_(B) receptor agonist is IRL-1620. 3.The method of claim 2, wherein the therapeutically effective amount ofIRL-1620 is about 5 μg/m² to about 11 μg/m².
 4. The method of claim 1,wherein the chemotherapeutic agent is a docetaxel.
 5. The method ofclaim 1, wherein the taxane-resistant cancer being treated is aprostate, breast, or ovarian cancer.
 6. The method of claim 1, whereinthe cancer being treated is a metastatic cancer.
 7. The method of claim1, wherein the cancer being treated is unresponsive to prior taxanechemotherapy.
 8. A method of treating a cholangiocarcinoma, comprising:administering a therapeutically effective amount of an endothelin B(ET_(B)) receptor agonist and a therapeutically effective amount ofchemotherapeutic agent to a subject suffering from a cholangiocarcinoma;wherein administration results in a reduction in the size or in thegrowth of the cholangiocarcinoma, thereby treating thecholangiocarcinoma.
 9. The method of claim 8, wherein the ET_(B)receptor agonist is IRL-1620.
 10. The method of claim 9, wherein thetherapeutically effective amount of IRL-1620 is about 5 μg/m² to about11 μg/m².
 11. The method of claim 8, wherein the chemotherapeutic agentis docetaxel.
 12. The method of claim 11, wherein the therapeuticallyeffective amount of docetaxel is about 60 mg/m² to about 75 mg/m². 13.The method of claim 8, wherein the cholangiocarcinoma is a metastaticcholangiocarcinoma.
 14. The method of claim 8, wherein the ET_(B)receptor agonist and the chemotherapeutic agent are administeredsubstantially simultaneously.
 15. A method of treating a metastaticcarcinoma, comprising administering a therapeutically effective amountof an endothelin B (ET_(B)) receptor agonist and a chemotherapeuticagent to a subject suffering from a metastatic carcinoma; whereinadministration results in a reduction in the size or in the growth ofthe metastatic carcinoma, thereby treating the metastatic carcinoma. 16.The method of claim 15, wherein the ET_(B) receptor agonist is IRL-1620.17. The method of claim 16 wherein the therapeutically effective amountof IRL-1620 is about 5 μg/m² to about 11 μg/m².
 18. The method of claim15, wherein the chemotherapeutic agent is docetaxel.
 19. The method ofclaim 18, wherein the therapeutically effective amount of docetaxel isabout 60 mg/m² to about 75 mg/m².
 20. The method of claim 17, whereinthe therapeutically effective amount of docetaxel is about 60 mg/m². 21.A method of treating a transition cell urothelial carcinoma, comprising:administering a therapeutically effective amount of an endothelin B(ET_(B)) receptor agonist and a chemotherapeutic agent to a subjectsuffering from a transition cell urothelial carcinoma; whereinadministration results in a reduction in the size or in the growth ofthe transition cell urothelial carcinoma, thereby treating thetransition cell urothelial carcinoma.
 22. The method of claim 21 whereinthe ET_(B) receptor agonist is IRL-1620.
 23. The method of claim 21,wherein the therapeutically effective amount of IRL-1620 is about 5μg/m² to about 11 μg/m².
 24. The method of claim 21 wherein thechemotherapeutic agent is docetaxel.
 25. The method of claim 24, whereinthe therapeutically effective amount of docetaxel is about 60 mg/m² toabout 75 mg/m².
 26. The method of claim 24, wherein the therapeuticallyeffective amount of docetaxel is about 60 mg/m².
 27. The method of claim24, wherein the therapeutically effective amount of docetaxel is about75 mg/m².